Grading apparatus.



'1. A. BECHTEL. GRADING APPAnATus.

APPLICATION FILED IAN. l2. |912'.

l. A. BECHTE'L. GRADING APPARATUS.

APPucATlou men JAN. 1 2. |912.

1,151,555. mma 51g. 31,1915.

2 snEsTs--snzn 2.v F1' un?? I WITNESSES: IN VEN TOR.

ro-HNA. EECHTEI., 0E TAEENTUM, PENNSYLVANIA, AsSIGNoE To PITTSBURGH PLATE GLASS COMPANY, 0E PITTSBURGH, PENNSYLVANIA, A CORPORATION 0E PENN- SYLVANI.

GRADING APEARATUS.

To all whom t may concern:

Be it known that I, JOHN A.y BEcHTEL, a citizen of the United States, residing at rlarentum, in the county of Allegheny and State of Pennsylvania, have invented certainl nism whereby the abrasive may be awn oft' from different levels in the tank. *l hese, together with such other objects as hereinafter appear, I attain by means of a construction illustrated in preferred form in the accompanying drawings, of which- Figure 1 is a side elevation of myimproved apparatus, partially broken away to more clearly show the parts, and Figure 2 is an end elevation of Figure 1.

I have shown the apparatus located above the usual sump 7 which is adapted to receive abrasive and lwater and is connected by means ofthe channels or gutters 8 and 9 to the ditches surrounding the grinding tables "and apparatus (not shown) usually employed in the grinding of plate glass. The grading apparatus comprises a tank, the lower portion 10 of which is of a conical shaperand the upper portion a cylindrical extension 11 of the cone. rlhe mixture of abrasive and water is forced into the bottom of the cone 10 from the sump by means of the centrifugal pump 12 which is operated by the motor 13 in any preferred manner, and is connected to the sump by .means of the pipe 14. The abrasive thus forced'into the tank from beneath upward is maintained in Suspension in the water and settles in the tank in grades, according to weight, the heavier particles remaining in the lower portion and the lightest being in the upper' or cylindrical portion. The outlet pipes 15-15 the pipes 17 -1 The outlet pipes or conduits 17 are each pro- Specication of Letters Patent.

Application led January 12, 1912. Serial No. 670,779.

Patented Aug. ai, 1915.

vided with a iexible intake 18, preferably composed of a hose provided with a head 19,

' which may be lowered and `raised at will by means of the cable 2O to draw off the ner v portions of thesand from different levelsl within the tank, depending either upon the level of the mixture within the tank or upon the particular grade of the lighter grades of the sand in the upper portion of the tank which may be desired for use. yFor finishing the grinding of the plates of glass on the grinding tables, the finest or lightest portions of the abrasive are required, and `it will be readily seen that by this construction the operator, by proper manipulation, can secure the finest of the lighter grades in the upper portion of the tank. i y

Adjacent the top of the tank, I have pro- I videdan overflow pipe 21'which is adapted` to carry off useless mud'and excess water,

portion 11 of the tank and on the outside thereof, I have provided a trough 22. Above the trough 'the tank is provided with an outlet pipe 23 leading into the trough and governed byithe valve 24.. When the vol -ume of abrasive and water forced into the 'tank by the pump 12 is too great, the valve 24 is opened and a portion of the-mixture 8 will flow into the trough and thence through the `pipe 25 back into the sump or elsewhere as may be desired.v This prevents'any loss 0f abrasive. The same a-rrangement'may be utilized for varying the operation so as to produce different grades in the cylindrical portion of-the tank. The pipes 17 are iexi-` ble, and as shown in the drawings, empty ad intermediate the ends of the cylindrical into troughs or channels 17 '-17 which lead y to the grinding tables not shown. The

pipes 15 and 16 may empty into the hoppers 26 and 27 'which lead to the sump or they may empty intovtrou'ghs which leadto .the

table or to vpits for containing the corresponding grade of abrasive which Athey draw from the tank, in the usual'` manner. In order to secure a Aiiovv of the mixture in thew sump into the pump, water under pressure is admitted into the sump adjacent the mouth of the pipe 14: through the pipe `27 which is suitably controlled by valve mechanism not l It will be observed that by this' construction there isno waste off-abrasive, that the grades of abrasive bestsuited' for the particular stage of the grinding'opera'tion can illustrated its use, what I claim as new and desire to secure by Letters Patent is the following:

1. In combination in a grading apparatus, a drainage receptacle for abrasive and water, al grading tank provided with an overiiow at its upper end and with an outlet intermediate its ends leading to the drainage receptacle, means for supplying the tank from the saidl receptacle and securing i an upward liow'of liquid through the tank,

and means for withdrawing portions of the liquid inthe tank from different levels between its upper and lower ends.

2. In combination in grading apparatus, a drainage receptacle for abrasive and water, a grading tank provided with an overiiow at its upper end and with an outlet intermediate its ends, a valve controlling said outlet, a trough belowY the said outlet into which the outlet discharges, a pipe leading from the trough to the said receptacle, means for supplying the tank from the said receptacle and securing an upward flow of liquid through the tank, andv means for'withdrawing vportions in the tank from different levels between its upper and lower ends.

3. In combination in a grading apparatus, a drainage receptacle for abrasive and water, a grading tank provided with an overflow at its upper end and with an outlet intermediate its ends leading to the drainage receptacle, means for supplying the tank from the said receptacle and securing an upward iow of liquid through the tank, a controlling valve for the saidoutlet and'means for withdrawing portions of the .liquid in' the tank from different levels between its upper and lower ends.

` 4. Incombination in a grading apparatus, a grading tank for abrasive, a drainage receptacle for abrasive and water, means for securing anv upward flow 'of liquid from the drainage receptacle through the tank, a plurality of outlet pipes in ,the tank having .their inlet ends at dierent levels and their 

